Time Systems

Typically there is a device for that purpose, called clock, which at least shows the remaining time for each player and who's turn it is.

Players hit it alternately to signal turn completion, stopping their side of the clock and resuming the other. Depending on the time system, this may trigger further actions. As soon a player exhausts all time[1], the player loses on time (no matter if the turn was complete[2] or not).

Turn based play fundamentally requires to handle time in a different way: although many of the timing systems above are usually available on such servers, these timing systems are less suited, in favour of:

Also, is there a way to play games without a game clock (eg with a normal clock, or countdown timer as found on watches and cell phones)? Is it possible to organise a tournament without game clocks (i.e. with a gong)?